From mboxrd@z Thu Jan 1 00:00:00 1970 In-Reply-To: Date: Mon, 7 Feb 2000 20:02:03 +0100 To: Geert Uytterhoeven , linuxppc-dev@lists.linuxppc.org CC: linux-fbdev@vuser.vu.union.edu From: Benjamin Herrenschmidt Subject: Re: [linux-fbdev] Retrace Message-Id: <20000207200203.007111@mailhost.mipsys.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: On Mon, Feb 7, 2000, Geert Uytterhoeven wrote: >And now the bad news: the address you have to mmap() depends on the machine >type :-( We need to find a solution for that one day or another. The iobase is not only arch-dependant (PReP, PowerMac, CHRP...) but also machine dependant, since it depends on the host bridge type. Unfortunately, with weird host bridges like Apple Uni-N (that has 3 busses with 3 different io bases but the same bus number), it's almost impossible to get it correct, or eventually by parsing /proc/device-tree. That means that getting code that need to do io's from userland is a real challenge. Even X is not completely correct in this regard. Ryuichi tried to fix it at least for PowerMacs, but gave up for Uni-N based machines. ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/